To view an Attendee’s available meeting times, you must first add one or more attendees to an event on the Info Panel and tab or click out of the Attendee field. When you do so, a button labeled Available Meeting Times appears, which when clicked displays the Availability Panel. You can also access the Availability Panel by choosing Window > Availability Panel (Shift-⌘-A).

A user can indicate on a per-event basis whether the event shows them as Busy or Free by choosing a status from the “show as” pop-up menu in the Info Panel for that event (for Exchange calendars) or by checking the “busy” box in the Info Panel (for CalDAV calendars).

To display the “show as” pop-up menu or the “busy” checkbox in the Info Panel, choose BusyCal > Preferences > Info Panel, and check the “Busy” checkbox. The “show as” pop-up menu (for Exchange calendars only) contains the following options that you can set on a per-event basis:

In order for a meeting organizer to see the availability of an attendee, the attendee must share their calendar with the organizer and grant the organizer the necessary access privileges.

Attendees can change access privileges by Control-clicking a calendar in the sidebar, choosing Get Info from the contextual menu, and choosing the desired option next to the organizer’s name:

For Exchange calendars only, if the attendee grants the organizer “Availability” access to their calendar, the organizer can see the attendee’s free/busy time only as gray blocks on the Availability Panel (see John Chaffee above).

Also for Exchange calendars only, if the attendee grants the organizer “Availability, Title, Location” or higher (Read Only, Read & Create, Read & Write, or Delegate) access to their calendar, then the organizer can see the attendee’s event titles on the Availability Panel (see Dave Riggle above).

For iCloud and CalDAV calendars, if the attendee selects the checkbox next to the organizer’s name in the Allow Write column, the organizer can see the attendees event titles, and can make changes to the attendee’s calendar.

Availability access can be granted only on your primary calendar.

Note: When syncing with Exchange, only events on your primary calendar affect your availability. Events stored on secondary calendars do not affect your availability and do not appear on the Availability Panel as blocking your free time. This limitation does not apply to CalDAV servers.